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(Reaffirmed 2003)

IS 10447 - 1983

Indian Standard
GUIDELINES FOR UTILIZATION AND DISPOSAL OF SOLID WASTES FROM INTEGRATED STEEL PLANTS.

UDC 628.544 (026) : 669.18.013.5

© Copyright 1983

INDIAN STANDARDS INSTITUTION
MANAK BHAVAN. 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002

Gr 3

April 1983

Indian Standard

GUIDELINES FOR UTILIZATION AND DISPOSAL OF SOLID WASTES FROM INTEGRATED STEEL PLANTS

Secretary

SHRI A. K. BAHL
Assistant Director (Chem), ISI

Indian Standard

GUIDELINES FOR UTILIZATION AND
DISPOSAL OF SOLID WASTES FROM
INTEGRATED STEEL PLANTS

0. FOREWORD

0.1

This Indian Standard was adopted by the Indian Standards Institution on 28 February 1983, after the draft finalized by the Solid Wastes Sectional Committee had been approved by the Chemical Division Council.

0.2

In any industry when basic raw materials are processed, along with the main products some other materials are also produced. Depending on the characteristics of these materials some of them, called by-products, may be economically used either in the same industry or in another industry, whereas the rest, called wastes, are totally discarded.

0.2.1

An Indian integrated iron and steel plant produces approximately 1.1 tonne of solid wastes for every tonne of ingot steel produced. This figure does not include ore fines and slimes of ore crushing plant at mines, and middlings or rejects at a coal washery.

0.3

Dumping sites of the solid wastes preferred for recycle should be located adjacent to the recycle process units. For example, solid wastes which are to be recycled to sintering plant should be dumped in close proximity to the sintering plant for effective recycling.

1. SCOPE

1.1

This standard prescribes guidelines for the present and possible future uses of the solid wastes generated in an integrated steel plant. Amount of generation and characteristics of these wastes have also been given.

1.2

This standard does not cover wastes generated at mines and collieries. It also does not include spillage at various stages of processing which is recycled into the system, for example, dust at coke ovens, sinter plant, etc, and also wastes generated in small quantities like dust from open hearth furnaces and sludge from water softening plants.

2. TERMINOLOGY AND SOURCES OF WASTES

2.1

Blast Furnace Gas Cleaning Plant Sludge—These are finer particles of dust finally removed from the blast furnace gas in the gas cleaning plant.

2.2

Blast Furnace Slag—This is the waste material, consisting mainly of CaO, SiO₂, Al₂O₃ and MgO, coming out of the iron making blast furnaces. It is originally in liquid form but is finally disposed off as a solid after cooling.

2.3

Bottom Ash—The coal used in the grate type boilers, after combustion, turns into clinker form which is known as bottom ash.

2.4

Coal Tar Sludge—This material collects below the tar in the coke ovens by-product plant. It is a soft solid mass which turns into fluid at a temperature around 75-80°C.

2.5

Fines and Dust from. Calcining Plant—These fines are generated during the processing of dolomite for the supply of sized material to steel melting shops. Lime and dolo dust are also generated during calcination of lime stone and dolomite in the kilns.

2.6

Flue Dust—The gas emitted by a blast furnace is laden with dust as it comes out of the furnace. During the gas cleaning process, the coarser particles, collected in the dust catcher, are called flue dust.

2.7

Fly Ash—Fly ash is a finely divided residue resulting from the combustion of ground of powdered coal and carried along with the flue gases of boilers fired by pulverized coal.

2.8

Foundry Wastes

1. Foundry Sand—Large amount of used silica sand, a part of which is burnt, generated as a waste in the foundry.
2. Cupola and Electric Furnace Slag—A slag generated during cupola or electrical furnace melting.

2.9

Mill Scale—While steel ingots or other sections are heated in soaking pits or reheating furnaces before rolling, the outer skin of the material is oxidised. The oxidised layer, called mill scale, drops down in the furnaces or under the rolling table.

2.10

Slimes—During crushing and washing of iron ore within the steel plant for improving its quality and size, finer fraction (less than 200 µm) is carried away by water in the form of slurry into a pond. These fine particles of iron ore are called slimes.

2.11

LD Converter/Open Hearth Slag—This material is generated during conversion of iron into steel in a steel making furnace.

2.12

Wastes from Refractories—Used broken bricks are generated during breaking of the refractory lining for rebuilding various furnaces.

Dusts of various refractory materials are produced during the manufacture of refractory mortars or bricks in integrated steel plants.

3. SOLID WASTES

3.1

The characteristics, quantity, and possible uses of the various solid wastes generated in an integrated steel plant are given in Table 1.

Note—The figures given are likely to vary from plant to plant depending on the raw materials used and operating conditions. Since the possible uses of wastes are dependent on their chemical and physical properties, corresponding variations are likely in this respect also.

*Suitable for re-cycling.
†Suitable for by-product recovery.
‡Guidelines for utilization and disposal of fly ash.

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